The invention pertains to the general field of programmable motors, and more particularly to an integrated closed-loop programmable motor assembly having a record mode in which a manually selectable route is recorded, and a playback mode in which the route can be automatically duplicated at a subsequent time.
The prior art is replete with designs and assemblies, which utilize at least one electric motor to perform a variety of tasks. Typically these motor drive assemblies operate a motor that is controlled by a microcontroller, which is controlled by a software program. Included in the software program is a calibration routine that is implemented before the normal automatic control operation commences. If an operating problem is detected, a fault routine becomes operable to either correct the problem or terminate the operation to allow maintenance to be performed on the assembly.
The above prior art motor control assemblies are generally complex and require several xe2x80x9cseparatexe2x80x9d components to comprise the overall assembly. Typically, these assemblies are used for tasks that are performed on relatively large and complex systems, such as used in the automotive and various machine shop industries. The applicant""s design differs from the prior art in that a minimum amount of elements are utilized and the entire system is housed within a single enclosure. Depending on its use, the applicant""s assembly can be produced with smaller components, as would be used in robotics, or with larger heavy-duty components, as used to operate larger machines.
A search of the prior art did not disclose any patents that read directly on the claims of the instant invention, however, the following U.S. patents were considered related:
The U.S. Pat. No. 5,668,456 discloses a servo motor encoder in which signals are outputted via signal lines and output terminals, which are used in common. Incremental signals and servo motor magnetic pole position detection signals are switched by a multiplexer so as to output these signals via a common line driver. Alternatively, two line drivers are selectively activated and inactivated so that incremental signals and servo motor magnetic pole position detection signals are outputted via common signal lines.
The U.S. Pat. No. 5,521,588 discloses a method and apparatus for programming a plurality of control devices which includes a central control device having a non-volatile configuration memory. A bus system connects all the control devices in the vehicle to one another and to the central control device. When one of the control devices is retrofitted or replaced, it initiates a comparison of data located in its memory with the vehicle configuration data resident in the configuration memory of the central control device. In case of differences between these data, the data in the retrofitted or replaced control device is overwritten with current vehicle configuration data called-up from the vehicle configuration memory.
The U.S. Pat. No. 4,866,630 discloses an automatic sawing machine having an automatic workpiece shuttle, shuttle and stationary vises, an automatic saw blade feed, one or more incremental motion encoders and a programmable microcomputer. The microcomputer is capable of storing a series of sawing jobs wherein each job has a number of sawing steps. The microcomputer receives signals from the motion encoders to determine the shuttle and tilt position and uses these positions to control shuttle, tilt and vise operation. The microprocessor also receives motion increment signals from the motion encoders which are decoded to determine the direction in which the increment was traveled, and which are decoded in a manner which increases conventional accuracy by four.
For background purposes and as indicative of the art to which the invention relates, reference may be made to the following remaining patents found in the search:
The integrated, closed-loop programmable motor assembly is designed with an internal memory that allows manually inputted data pertaining to the rotational speed and the angular displacement of an electric motor shaft to be recorded. The recorded data is then automatically reproduced when the motor is placed in a playback mode. In its basic design, the integrated, closed-loop programmable motor assembly is comprised of
A bi-directional electric motor which operates in a record mode and in a playback mode. When the motor, which is connected to a load and to a motor shaft encoder, is operated in the record mode, the motor shaft is manually rotated which allows the motor shaft encoder to produce an encoded digital signal corresponding to the rotational speed and angular displacement of the motor shaft;
A rotation decoder which is applied the encoded digital signal and produces a decoded digital signal corresponding to the rotational speed and angular displacement of the motor shaft; and
A microcontroller having an internal memory. When the assembly is placed in the record mode, the decoded digital signal is stored in the microcontroller""s internal memory. When the assembly is placed in the playback mode the microcontroller produces a motor drive signal. The motor drive signal is applied to a motor drive circuit, which produces a motor interface signal that applied to and allows the motor to automatically duplicate the speed and angular displacement of the motor shaft produced during the record mode.
To further enhance the design of the assembly, a time-pulse generator and an assembly control circuit are included with the basic design. The generator controls the precise timing sequence required to operate the assembly; the control circuit allows an operator to access and control the operation of the assembly. The assembly can be designed to operate with an internal battery, which allows the assembly to function as a stand-alone unit, or the assembly can incorporate an internal regulated power supply, which is connected to a utility power source by means of a power cable assembly.
During the record mode the motor shaft is manually rotated to traverse a particular speed and motion desired. A crystal controlled oscillator located in the time-pulse generator is used to produce synchronous timing pulses, which are produced periodically such as every {fraction (1/100)}th of a second. The motor shaft encoder attached to the motor shaft produces counts corresponding to the rotational speed and angular displacement of the motor shaft, for example 360 counts per shaft revolution. Each time a timing pulse is produced it is applied to the rotation decoder from where a corresponding decoded digital signal is produced that is subsequently applied to and stored in the memory circuit of the microcontroller. Thus, the microcontroller memory stores the physical position of the motor shaft for every {fraction (1/100)}th of a second. In other words, the memory stores 100 shaft counts per second where each count corresponds to the amount of shaft movement within each {fraction (1/100)}th of a second.
During the playback mode the memory is synchronously accessed at the same time increments that occurred during the record mode. The memory is read by the microcontroller, which then produces a motor drive signal that drives the electric motor until the recorded signal of the motor rotation is reached. This process continues at a rate of 100 times a second until the final memory position is reached.
In a typical application of the assembly, the electric motor is first programmed by placing it in the record mode and then manually rotating the motor shaft to describe a desired motion. The motor shaft can be made to rotate any amount, in any direction, for any period of time. During the record mode, digital data corresponding
To the motor shaft rotation is read from the motor shaft encoder and stored in the memory circuit of the microcontroller. This data is recorded time synchronous, based on the time pulse produced by the time pulse generator. When the assembly is placed in the playback mode the stored position data is synchronously read by the microcontroller via the rotation decoder, and the motor rotates to reproduce the rotational data manually inserted during the record mode.
In view of the above disclosure, the primary object of the invention is to produce an integrated; closed-loop programmable motor assembly, which is packaged in a single enclosure and that, operates in a record mode and in a playback mode. In the record mode the assembly is manually programmed, in the playback mode the data acquired during the record mode is automatically duplicated. In addition to the primary object of the invention, it is also an object of the invention to produce an assembly that:
can be produced in various sizes to accommodate the particular load requirement of the assembly;
can be used to operate robotics, various machinery and toys,
can be designed to operate with an internal power source as a self-contained assembly, or can be designed with an internal power source that is connected, via a power cable assembly, to an a-c utility power source,
is reliable and relatively maintenance free, and
is cost effective from both a manufacturer and consumer""s point of view.
These and other objects and advantages of the present invention will become apparent from the subsequent detailed description of the preferred embodiment and the appended claims taken in conjunction with the accompanying drawings.